Food processors are well known that are constituted by a base containing a motor whose drive shaft projects from the top surface thereof, and by a bowl capable of being engaged on said motor support to receive in succession a plurality of tools which are rotated inside the bowl by said drive shaft. One such appliance is described in FR-A-2 147 361 (Verdun), in particular.
Proposals have already been made to secure the bowl to the support in its center by providing a sheath or ferrule that projects above the base around the drive shaft and that carries regularly spaced apart projections near its top end. Under such conditions, the bowl itself includes a central protective chimney whose inside contains corresponding projections which, when the bowl is in its working position, serve to retain the bowl against vertical forces. In a mounting of that kind, it is known to provide an abutment piece at the periphery of the bowl to prevent the bowl from rotating under drive from the tools and the food being processed within the bowl. Otherwise the bowl might be entrained by friction against the walls of the bowl from the food being processed. In addition, in order to avoid any contact between a hand and the tools while they are rotating, the bowl must necessarily be closed by a lid while the tools are being rotated. To this end, a lid is removably fixed to the top of the bowl. Such closure is generally obtained by a bayonet type fastening. However, the direction in which the lid is fastened on the bowl is the same as the direction in which the bowl is fastened on the base. In other words, once both of the above operations have been performed, if it is desired to remove the lid before removing the bowl from the base, then it is necessary to prevent the bowl from rotating by using anti-return means that oppose rotation of the bowl in the clockwise direction, and more generally in the direction opposite to the tool-rotation direction.